This invention relates to froth flotation chambers or columns, and especially to apparatus of the type in which fine particle size mineral impurities as the brownish mineral anatase can be separated by flotation from an aqueous slurry of kaolin clay, a white mineral which has a higher commercial value with increased whiteness.
Many types of flotation equipment have been proposed for separating mixtures of discrete mineral particles from a slurry containing both types of particles. Generally, air bubbles are formed in the slurry. These air bubbles contact the mineral particles, some of which adhere to the bubble. This froth rises to the top of the vessel containing the slurry. Then, the froth is effectively separated from the remaining slurry; likewise, the other mineral particles to be separated remain in the slurry and flow to the bottom of the chamber as tailings. Various flotation chambers have been described in the literature, namely, in U.S. Pat. No. 4,477,338 to Hellmann, U.S. Pat. No. 1,112,853 to Callow, U.S. Pat. No. 3,202,281 to Weston, U.S. Pat. No. 3,464,552 to Warman, U.S. Pat. No. 3,371,779 to Hollingsworth et al., U.S. Pat. No. 2,178,239 to McKenna, U.S. Pat. No. 4,287,054 to Hollingsworth, U.S. Pat. No. 4,394,258 to Zipperian, U.S. Pat. No. 4,472,271 to Bacon, Jr., and U.S. Pat. No. 4,212,730 to Brooks.
It has been desired to produce an improved flotation chamber suitable for use in beneficiating kaolin, in which very fine bubbles are injected to aerate the slurry, and which has quiescent zones both above and below the level of bubble generation.